When fabricating a Thin Film Transistor Liquid Crystal Display (TFT-LCD) panel, there may be broken data lines in the panel due to various reasons. In this case, pixels corresponding to a broken data line can not receive output data and an obvious bright line (or dark line) may appear when the panel is powered on. Such a defect is unacceptable to consumers while discarding the panel directly may cause significant waste.
For overcoming the above issue, a conventional technology provides the following technical solution: a data drive output channel corresponding to the broken data line is routed to a Printed Circuit Board (PCB) by laser welding and connected to an input terminal of an operational amplifier buffer (OP buffer), an output terminal of which is connected to a reserved test line in the panel. The test line is then connected to another segment of the broken data line by laser welding and the display of the segment of the broken data line may be charged by the test line. By this means, a line defect is turned into a dot defect, which generally will not severely affect display quality of the LCD. However, routing to the PCB is necessary for such a method to repair the broken data line, which greatly increases the routing distance of the data line and RC loading of the routing; as a result, an OP buffer should be added on the PCB to drive the broken data line. Since dimensions of the LCD panels are ever growing and the routing distance is increased accordingly, the RC load of the control signal transmitted on the wiring is also increased, which severely degrades the transmitted signal and a single OP buffer can not meet actual requirements.